扫描二维码，直接登录
题库 / GMATAdvanced-CR-21
Researchers in City X recently discovered low levels of several pharmaceutical drugs in public drinking water supplies. However, the researchers argued that the drugs in the water were not a significant public health hazard. They pointed out that the drug levels were so low that they could only be detected with the most recent technology, which suggested that the drugs may have already been present in the drinking water for decades, even though they have never had any discernible health effects.
Which of the following, if true, would most strengthen the researchers’ reasoning?
If a drug found in drinking water is not a significant public health hazard, then its presence in the water will not have any discernible health effects.
There is no need to remove low levels of pharmaceutical drugs from public drinking water unless they present a significant public health hazard.
Even if a substance in drinking water is a public health hazard, scientists may not have discerned which adverse health effects, if any, it has caused.
Researchers using older, less sensitive technology detected the same drugs several decades ago in the public drinking water of a neighboring town but could find no discernible health effects.
Samples of City X’s drinking water taken decades ago were tested with today’s most recent technology, and none of the pharmaceutical drugs were found.
D加强; 很多年前老的机器检测出了这种药，然而并没发现会影响健康。
（这里还暗含了老机器检测出了的药量比较高，既然高的药量都没影响，那用新机器检测出来的很低的药量对健康更没影响了）
所以不会对人们的健康造成危害。
加强：
level so low，存在很多年与健康的关系/ 其他因素对健康影响
首先确认结论是not public hazardous
当时还在想这个跟题目没关系的事情——老的检测出说明更多，还没发现影响健康，那不就是不public...了么
太尼玛傻了
原因： 它们已经长期存在在水里头，到现在都没有看到有威胁到公共健康。
D：多年前老机器也能检测出这种有害物质，但没发现会影响健康。
【一是肯定了“存在很多年了”这个推测，而是暗含多年前有害物质含量更高（老机器都能检测出来）对健康都没有影响，加强了“这个物质无害”的结论】
答案橋搭得很完善: 很久以前藥含量高都證明沒事了
加强 D 旧技术几年前在邻镇检测出来了表明对健康没影响 说明了1,3，在其他地方监测的可能含量不一样 2可以不一致
E 削弱 几年前的样本用新技术监测出来没有药——-哇和1矛盾了
A把结论进行if，如果结论成立，那么药不用移除，没法加强结论
B除非药是对公众健康的威胁，否则不需要移除。跟A是一个意思。
D，以前监测过，没监测出来。结合原文内容看，这可以印证之前提到过的只有用最新技术才能监测出来，也印证了药的含量低的事情。注意这里有一个限定，the public drinking water of a neighboring town，监测的邻近镇的水，而不是city X的水，是存在一定差异的。一其它选项都不能很好地加强；二构建场景，这里监测的应该是诸如地下水、自然水等统一的供水系统，隔壁镇与city X可以共用一套水源，比如上海的自来水来自于崇明xx采水点，不管静安区还是闸北区的自来水都来自这个采水点；农夫山泉江浙沪的采水点都在千岛湖。
赞同
赞登录 或 注册 后可以参加讨论